10 units · 90 conversions

Length Converter

Convert between metric and imperial length and distance units.

Popular Length conversions

Meters to Kilometers m → km Meters to Centimeters m → cm Meters to Millimeters m → mm Meters to Micrometers m → µm Meters to Miles m → mi Meters to Yards m → yd Meters to Feet m → ft Meters to Inches m → in Meters to Nautical Miles m → nmi Kilometers to Meters km → m Kilometers to Centimeters km → cm Kilometers to Millimeters km → mm Kilometers to Micrometers km → µm Kilometers to Miles km → mi Kilometers to Yards km → yd Kilometers to Feet km → ft Kilometers to Inches km → in Kilometers to Nautical Miles km → nmi Centimeters to Meters cm → m Centimeters to Kilometers cm → km Centimeters to Millimeters cm → mm Centimeters to Micrometers cm → µm Centimeters to Miles cm → mi Centimeters to Yards cm → yd Centimeters to Feet cm → ft Centimeters to Inches cm → in Centimeters to Nautical Miles cm → nmi Millimeters to Meters mm → m Millimeters to Kilometers mm → km Millimeters to Centimeters mm → cm

All Length conversions (90)

All Length units

Meters m Kilometers km Centimeters cm Millimeters mm Micrometers µm Miles mi Yards yd Feet ft Inches in Nautical Miles nmi

About Length

Length is the measurement most people need to convert first, and this category covers the ten units that turn up in everyday life and in technical work: meters, kilometers, centimeters, millimeters and micrometers on the metric side, plus miles, yards, feet and inches from the imperial and US customary systems, and nautical miles for sea and air navigation. The people who land here are rarely doing pure maths. They are reading a product listing that gives a screen size in inches, following a running plan written in kilometers, cutting timber from a plan drawn in millimeters, or checking a height that a form insists on in feet. The most heavily used pages are the ones that bridge the two systems: meters to feet, centimeters to inches, kilometers to miles and inches to millimeters.

The useful thing to understand about length is that the split is geographic rather than technical. Almost every country builds, sells and legislates in metric units, so meters and millimeters dominate engineering drawings, science and international trade. The United States kept customary units for construction, personal height and road signs, and the United Kingdom sits in the middle: road distances and speeds are still in miles, but shop weights and most trades work in metric. That is why so much conversion is needed at all. Two units are worth a second look. The nautical mile is not a variant of the ordinary mile, it is a navigation unit tied to the geometry of the Earth, which is why pilots and sailors use it and why a distance in nautical miles never matches the same number in statute miles. The micrometer is a precision unit used for tolerances, coatings and particle sizes, and it is easy to confuse with the millimeter when reading a spec sheet quickly.

Every conversion page in this category does the same three things. It shows the formula it applied, so you can see the arithmetic rather than trust a black box. It works through a real example with your kind of numbers. And it gives you a reference table of common values, which is often faster than typing anything in when you just want a rough figure. All of it is free, there is no sign-up and no limit on how many conversions you run, and the maths happens entirely in your own browser, so nothing you type is uploaded anywhere. If you need to size a room rather than a line, the area converter is the companion hub.

Frequently asked questions

What is the difference between a mile and a nautical mile?

They are separate units for separate jobs. The ordinary statute mile is the one on road signs in the US and UK. The nautical mile is a navigation unit based on the geometry of the Earth, which makes it convenient for charts and latitude, and it is used at sea and in aviation. A nautical mile is the longer of the two, so a distance quoted in one is never the same number in the other. Use the nautical miles pair pages if you are working from a chart or a flight plan.

Which length units are metric and which are imperial?

Meters, kilometers, centimeters, millimeters and micrometers are metric, and they all relate to each other by powers of ten, which makes them easy to shift between. Miles, yards, feet and inches are imperial or US customary and use their own step sizes. The nautical mile belongs to neither system in everyday terms and is used for navigation. Most conversions people actually need cross between the two groups, which is why pages like meters to feet and centimeters to inches are the busiest.

Why do I get a slightly different answer than a printed table?

Printed tables and quick mental rules are usually rounded. This converter carries the full precision of the standard factor and then rounds the result for display, so a figure may differ in the last digit or two from a rule of thumb someone taught you. For everyday use the difference is meaningless. For machining, engineering tolerances or anything where the last decimal matters, use the figure the page gives you rather than a rounded shortcut.

Do I need to create an account or install anything?

No. Every page in this category is free to use, there is no sign-up, no download and no cap on how many conversions you can run. The calculation runs in your browser using JavaScript, so the numbers you enter are never sent to a server. You can bookmark any pair page and go straight back to the conversion you use most.

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